A recorded signal reproducing method for an optical recording medium that is adapted to accurately reproduce a signal recorded on the optical recording medium having wobbled tracks. In the method, a signal included in the optical recording medium is picked up and a specified period of signal included the picked-up signal is detected. The picked-up signal is compensated in accordance with the specified period signal.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of reproducing a recorded signal on an optical recording medium, comprising the steps of: (A) picking up a signal included in the optical recording medium; (B) detecting a specified periodic signal included in the picked-up signal; (C) controlling a gain of the specified periodic signal; (D) compensating the picked-up signal in accordance with the controlled signal in the step (C); (E) re-detecting the specified periodic signal from the compensated signal; and (F) controlling further a gain control amount of the specified periodic signal in accordance with the re-detected specified periodic signal.
2. The method as claimed in claim 1 , wherein the specified periodic signal includes a wobbling signal derived from the wobbled track of the optical recording medium.
3. The method as claimed in claim 1 , wherein the specified periodic signal is a noise component introduced in the step (A).
4. The method as claimed in claim 1 , wherein the step (F) includes: controlling a gain control amount of the specified periodic signal in such a manner that the magnitude of the re-detected specified periodic signal has a value of 0 .
5. The method as claimed in claim 4 , wherein the step F includes: producing a signal depending on an amplitude and phase of the re-detected specified periodic signal; and applying the signal depending on an amplitude and phase of the re-detected specified periodic signal as a signal for indicating the gain control amount.
6. The method as claimed in claim 5 , herein the producing step includes multiplying the re-detected specified periodic signal by the specified periodic signal detected in the step (B) and integrating the multiplied signal.
7. An apparatus for reproducing a recorded signal on an optical recording medium, comprising: a pickup for picking up a signal contained in the optical recording medium; detecting means for detecting a specified periodic signal from the picked-up signal; combining means for combining a gain-controlled specified periodic signal from a gain control means with the picked-up signal from the pickup and thereby outputting a combined signal; and the gain control means for controlling a gain of the specified periodic signal from the detecting means based on the combined signal and thereby outputting the gain-controlled specified periodic signal.
8. The apparatus as claimed in claim 7 , wherein the specified periodic signal includes a wobbling signal derived from a wobbled track of the optical recording medium.
9. The apparatus as claimed in claim 7 , wherein the specified periodic signal is a component introduced when the pickup picks up a signal on the optical recording medium.
10. The apparatus as claimed in claim 7 , wherein the gain control means includes: variable amplifying means for variably amplifying the specified periodic signal from the detecting means, second detecting means for re-detecting a specified periodic signal from the combined signal output from combining means; and gain calculating means for producing a gain control signal to be applied to the variable amplifying means on a basis of an amplitude and phase of the specified periodic signal from the second detecting means.
11. The apparatus as claimed in claim 10 , wherein the gain calculating means produces the gain control signal in such a manner that the magnitude of the specified periodic signal detected by the second detecting means has a value of 0 .
12. An apparatus for reproducing a recorded signal on an optical recording medium, comprising: a pickup for picking up a signal included in a signal included in the optical recording medium; detecting means for detecting a signal portion corresponding to a specified period of the signal included in the signal from the pickup; combining means for combining the signal portion corresponding to a specified period of the signal from the detecting means with the signal from the pickup; and gain control means for controlling a gain of the signal portion corresponding to the specified period of the signal transferred from the detecting means to the combining means, wherein the gain control means includes, variable amplifying means for variably amplifying the signal portion corresponding to the specified period of the signal transferred from the detecting means, second detecting means for detecting a signal portion corresponding to the specified period of the signal from an output signal of the combining mean, and gain calculating means for producing a gain control signal to be applied to the variable amplifying means on a basis of an amplitude and phase of the signal portion corresponding to the specified period of the signal from the second detecting means.
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December 23, 1998
June 18, 2002
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